heightfield TERRAIN MATERIAL/TEXTURES

[Marythebest537]

Hi,

I'm trying to create a terrain, which I will probably export as .hda in UE4. At the moment I want to apply a material to this heightfield, where for each layer mask I want to apply textures and additive color layers, or more materials with relative textures for each mask (for example. slope mask-> material with texture1(base color, specular, roughness), curvature mask -> material2 with texture2(base color, specular, roughness) etc...). I tried to:

- use the heightfield_quickshade node, but it allows me to add only four textures; I tryed to create two heightfield_quickshade node but I can't merge these nodes;

- use more materials but I don't know to associate them all at the same heightfield;

Can someone help me to understand or give an example of how I can associate these masks with more than four textures which include(specular, roughness, normal...) and in case other masks as additive color layers, please? 

I attached my file

Heightfield_UE4.hipnc